TpchKhoahcHQGHN,KhoahcTnhinvCngngh25,S3S(2009)461471

461
_______
nh gi vai tr v mc tiu ca cc h cha
lu vc sng Ba
Nguyn Hu Khi*, Nguyn Vn Tun
Khoa Kh tng Thy vn v Hi dng hc, Trng i hc Khoa hc T nhin, HQGHN
334 Nguyn Tri, H Ni, Vit Nam
Nhn ngy 25 thng 11 nm 2009
Tm tt. Bo co trnh by cc nghin cu phn tch nh gi vai tr ca cc h cha sng Ba
trong cc nhim v phng chng l, pht in, cp nc phc v pht trin kinh t- x hi v m
bo mi trng trn lu vc v b sung nc cho lu vc khc. ng thi cng phn tch nh gi
mc tiu hin thi ca tng h cha v ton h thng lin h, s tng thch v khng tng thch
trong hot ng ca chng cho mc tiu chung. Trn c s kin ngh nhng thay i cn thit
trong cc mc tiu v vn hnh ton h thng m bo ngn l, chm l, an ton vn hnh h cha
v s dng hp l ti nguyn nc v ma kit lu vc sng Ba, p ng li ch hi ho v hiu
qu nht.
1. iu kin t nhin v x hi lu vc sng
Ba

1.1. iu kin t nhin
1.1.1. c im a l t nhin [1]
Sng Ba l mt sng ln min Trung Vit
Nam, din tch ton b lu vc xp x 14.000
km
2
, trn a phn ca ba tnh Gia Lai, ak lc
v Ph Yn, lu vc nm trong khong 108
o

n 109
o
27 kinh ng v t 12
o
30 n
14
o
40 v Bc (hnh 1).
Sng Ba bt ngun t nh ni Ngc R
thuc di Trng Sn, on thng ngun n
trm thu vn An Kh sng Ba chy theo
hng Ty Bc - ng Nam. Sau sng chy
theo hng ng Bc - Ty Nam tip theo l
hng Bc Nam v n Cheo Reo. T Cheo
Reo sng chy theo hng Ty Bc - ng
Nam v n Sn Ho v t y sng chy theo
hng Ty - ng ra bin ng.

Tc gi lin h. T: 84-4-38370599
E-mail: nhkhai47@gmail.com
Lu vc sng Ba c hnh ch L, thng
ngun nh, sau phnh ra phn trung lu
vc, ri li thu hp phn h lu vc trc khi
ra bin ng. Nhn chung a hnh lu vc
sng Ba rt phc tp c to ra bi s chia ct
ca di Trng Sn, cao nguyn v ng bng,
to nn nhng thung lng sng c dc ln.
cao bnh qun lu vc khong 500 m. Sng
Ba c nhiu sng nhnh, c hn 50 sng nhnh
c chiu di ln hn 20 km, 19 sng nhnh c
din tch lu vc ln hn 100 km
2
. c bit c
3 sng nhnh chnh l Ayun, KrngHnng
v sng Hinh.
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471 462

T AnKh-Kanak
H S. Ba h
Hnh 1. Lu vc v h thng h cha sng Ba.
Kh hu trn lu vc sng Ba l kh hu
nhit i gi ma chu s chi phi ca a hnh
mt cch su sc. Do b chia ct bi dy
Trng Sn pha Ty, o Hi Vn pha
bc v cc dy ni ct ngang ra bin pha nam
m kh hu lu vc sng Ba mang nt c trng
ring.

Cc i cc trn ma mt ngy m trong
khu vc thuc loi ln Vit Nam: Ti An Kh
t 240.8mm (1987), ti Sng Hinh 674mm
(1981), ti Sn Ho 579mm (1992), ti Sn
Thnh t 502mm (nm 1993) v ti Tuy Ho
t 628 mm (nm 1993). Thi gian ma ln
nht v thi gian xut hin l ln nht trn sng
c s lch pha khng ng k.
Do c s khc bit v kh hu gia cc vng
trn lu vc sng Ba nn c im l trn lu
vc Sng Ba rt phc tp, thi gian l thng
ko di t 7 n 9 ngy, thi gian l ln t 2
n 3 ngy. Trn lu vc nh l xut hin
cc sng nhnh v sng chnh thng khng
trng nhau; v d nm 1981 nh l xut hin
ti An Kh vo ngy 9/XI, ti sng Hinh 10/XI
cn ti Cng Sn l 18/XI. L sng Ba thuc
loi l ln, cc nh l thng xut hin ch
yu vo thng X v XI, m un nh l trung
bnh An Kh khong 920 l/skm
2
, ti Cng Sn
khong 660 l/skm
2
. Trn lu vc sng Ba xut
hin ba trn l lch s vo nm 1938, 1964 v
nm 1993.
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471 463

Ma kit trn lu vc sng Ba ko di 9
thng (i vi vng h lu, t thng 1 n
thng 9 vi tng lng dng chy ch chim
25% n 30% tng lng dng chy nm v
vng thng lu ko di 6 thng t thng 11
n thng 4 nm sau, tng lng dng chy
chim 25% n 30% tng lng dng chy
nm. c bit vng h lu, trong nm cn c 2
thi k kit, thi k th nht xut hin vo
thng 4, thi k kit th 2 xut hin vo thng
8. Hai thng 7 v 8 lng dng chy ch chim
3,2% lng dng chy nm.
1.1.2. H thng h cha lu vc sng Ba [2]
s dng v khai thc hiu qu ti
nguyn nc, cc h cha trn lu vc sng Ba
c xy dng. Hin nay h cha Ayun h
xy dng, c dung tch hiu dng l 201.10
6

m
3
, dung tch cht l 52.10
6
m
3
, mc nc dng
bnh thng l 204m, mc nc cht: 192m,
cung cp nc ti cho 13500 ha. Dung tch
phng l ca Ayun h l 25,5.10
6
m
3
. in
nng kh nh, cng sut ch khong 3 MW. H
cha sng Hinh cung cp in nng l chnh vi
cng sut 70 MW, c dung tch hiu dng
323.10
6
m
3
, mc nc dng bnh thng 209m,
mc nc cht 196m. H cha sng Ba H bt
u a vo hot ng c dung tch ton b l
165,9.10
6
m
3
, dung tch cht l 183,810
6
m
3
,
mc nc dng bnh thng:112,5m, cng sut
pht in 220MW. Hin nay cc h cha thu
in AnKh-Kanak vi dung tch 285,5.10
6
m
3

v cng sut 173MW, Krng Hnng vi dung
tch 242.10
6
m
3
v cng sut 65MW ang c
xy dng. Tuy nhin cc h cha ny c kh
nng iu tit hn ch. Cn c mt s h cha
v p dng ang c quy hoch v c th xy
dng trong tng lai nh h sng Ba Thng,
k rng v.v. Ngoi ra cn c hng trm h
cha nh khc phc v ti phn b trn cc
nhnh sng. Nhn chung h thng h cha
to c ngun nc v cung cp cho cc nhu
cu dng nc ca cc ngnh trn lu vc. H
thng h cha lu vc sng Ba ch ra trn hnh
1 v bng 1 .
Bng 1. Thng s chnh ca bc thang h cha sng Ba
Thng s
Flv
km
2

MNDBT
m
MNC
m
Wtb
10
6
m
3

Whi
10
6
m
3

Ka Nak 833 515 480 313.7 298.2
Ia Yun H 1670 204 195 253 201
Krng Hnng 1168 260 250 356.6 242.9
Sng Ba H 11115 105 101 349.7 165.9
Sng Hinh 772 209 196 357 323

1.2. iu kin kinh t x hi [1]
1.2.1. Hin trng pht trin kinh t
Lu vc sng Ba tri di 3 tnh Ty Nguyn
l Kon Tum, Gia Lai, k Lk v 1 tnh Duyn
hi Min Trung vi 19 huyn th v 1 thnh
ph, c tim nng kinh t tng hp v chu s
chi phi bi nn kinh t th trng y si ng
vi c cu kinh t Nng lm Cng nghip
Dch v v du lch ngoi ra vng h lu cn c
c cu thu sn do c li th v nui trng v
nh bt thu sn. y l lu vc c v tr quan
trng v kinh t v an ninh quc phng ca
vng Ty nguyn v ven bin min Trung. C
cu pht trin kinh t t trc n nay vn ly
Nng Lm - Nghip l chnh nn gi tr GDP
trong nng nghp vn chim t trng cao, nm
1998 chim 52,6%; nm 2000 chim 48,5%;
nm 2004 gim cn 46% trong tng gi tr cc
ngnh kinh t trong lu vc. Tuy vy nn kinh
t nng lm nghip ang c chiu hng gim
dn tng gi tr c cu cng nghip - dch v
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471 464
du lch cho ph hp vi xu th pht trin kinh t
chung ca t nc. Nhn chung c cu kinh t
gia cc vng trong lu vc sng Ba bin ng
khng ng u. Tng gi tr GDP trong cc
ngnh kinh t trn ton lu vc sng Ba nm
1998 l 5425 t ng, nm 2000 l 6241 t
ng v nm 2004 l 6594 t ng. Nhn chung
nn kinh t trn lu vc sng Ba vn tng
trng u vi nhp bnh qun 1998 n
nm 2004 t 10,35%/nm.
1.2.2. nh hng pht trin n nm 2015
v 2020
D kin ngun nhn lc trn lu vc Sng
Ba vo nhng nm 2010 v 2020 l c bn n
nh dn s hin c trn a bn cc huyn ca
lu vc trn c s n nh, nh canh, nh c,
gin dn vng th trn, th t. ng thi tip
nhn v b tr dn kinh t mi t tnh khc v
cc vng trng im kinh t v cng c an ninh
quc phng theo ch o ca Trung ng. Theo
quy hoch s dng t ai trn lu vc sng Ba
n nm 2010 v sau nm 2010 cho thy: Trc
mt s dng c hiu qu din tch t nng lm
nghip hin c, tp trung i theo hng sn
xut hng ho, thm canh tng v, p dng cc
tin b khoa hc k thut vo sn xut nng
lm nghip tng nng sut cy trng vt
nui. Pht trin din tch la nc v ng
Xun t 37.312ha (nm 2004) ln 47.228 ha
(nm 2010). ng thi gim la nng ry t
17.684 ha (nm 2004) xung cn 5300 ha (nm
2010) dn n nm 2015-2020 trit tiu hon
ton la nng ry trnh xi mn bc mu
t v nn t ph rng u ngun.

Mc tiu pht trin cng nghip vng d n
l cng nghip ho v hin i ho vi nhp
tng bnh qun theo gi tr gia tng cng nghip
thi k 2005 n 2010 l 15% v 2020 l
18,5%. Nng t trng cng nghip ln 25% vo
nm 2010 v 30% vo nm 2020. u tin pht
trin cc ngnh cng nghip mi nhn da trn
ngun lc sn c v ngun lc bn ngoi. m
bo 90% nc sinh hot v cng nghip vo
nm 2010 cho 3 th x An Kh v EaKa (mi
thnh lp) v thnh ph Tuy Ho v 100% vo
nm 2020. Cn li cc th trn m bo cp
nc sinh hot t 100% vo nm 2010. Thng
qua chng trnh nc sch nng thn phn u
m bo 80% dn s s dng nc sch vo
nm 2010 v 100% vo nm 2020, c bit
quan tm vng su, vng xa, vng c ng bo
dn tc t ngi
n nm 2020, tng lng nc yu cu:
3656,8. 10
6
m
3
, trong : nc cho nng nghip
v chn nui: 2812,5.10
6
m
3
, chim 77% tng
lng nc yu cu; nc cho nui trng thu
sn: 52.10
6
m
3
, chim 1%; Nc cho cng
nghip, dn sinh: 164,1.10
6
m
3
, chim 4%; nc
mi trng, duy tr dng chy: 627,8.10
6
m
3
,
chim 17%.
2. nh gi vai tr v mc tiu ca cc h
cha lu vc sng Ba
2.1. nh gi vai tr ca cc h cha
Tng s h cha trn sng Ba trn a bn 2
tnh Ph Yn v c Lc v Gia Lai l 260 h
cha k n nm 2009. Nh vy tc pht
trin h cha kh nhanh, c bit l h cha
nh. H s pht trin h khong 10 h/nm.
Mc iu tit ca h c th hin qua h s
iu tit =
D
tb
W
V
bin thin t 0,1 n 0,3 iu
chng t mc khai thc ny < 30% W
0

do khai thc mc bn vng.
Hin nay trn lu vc pha h lu hai bn
t hu c knh chnh bc nam p ng
Cam kt hp giao thng l ng lin tnh 7B
(bc) v 436 (nam) nhng nhiu on khi c l
ln nc vn trn qua. Trn lu vc hin ti c
2 h cha a mc tiu trong c nhim v
phng l l h Ayun h v h Sng Hinh.
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471 465

Ngoi ra cn c h cha sng Ba h, h Krng
Hnng, h An Kh Kanak.ang c xy
dng. Cng trnh ln ct l cho lu vc sng
Ba gp phn gim l cho h du khng ng k.
H Ayum h xy dng pha trung lu sng
Ba. H c dung tch phng l l 153 x 10
6
m
3
,
h sng Hinh l 252,5 x 10
6
m
3
, tng hai cng
trnh ny l 403,5 x 10
6
m
3
. Cc cng trnh cn
li dung tch phng l khng ng k, trong khi
tng lng l 7 ngy max ca nm 1981
khong 2,771 t m
3
v nm 1993 l 2,6 t m
3
.
Hai h trn ch c kh nng ct l khong 20%
i vi h lu khi c con l khong 10%. H
cha sng Ba H c tng dung tch 349,710
6
m
3
,
nh hn rt nhiu so vi cc trn l ln xy
ra trn sng Ba.
Trc nm 2000 vng ven sng Ba thuc
a phn huyn Krng Pa thng b ngp v
ma l. c bit l vng h lu sng Ayun
trc nm 2000 vng ny thng b ngp vo
thi gian u thng 10 v thng 11. Nhng t
sau nm 2000 tr li y khi cng trnh thu li
h Ayun h i vo khai thc vn hnh th
trng hp l lt xy ra y khng nhiu,
din tch ngp ng gim ch cn 225ha. Thi
gian ngp ngn li v ch xy ra trong thng 7
n thng 9, mi nm ch b 2 n 3 t v sau
1 tun l nc rt ht. Vi hai h cha phi hp
ct l Ayun h v sng Hnh (phng n 1-
PA1) th h thp ct nc dc ng nh
hn phi hp 5 h ct l (PA2- Ayun h, sng
Hnh, An Kh Kanak, Krng Hnng v sng
Ba h): Ti Cng Sn PA1 gim 0,84m; PA2
gim 3,05m. Ti Ph Lm PA1 gim 0,24m;
PA2 gim 3,83m. Mt khc vi mc nc trc
l khc nhau th mc gim Hmax cng khc
nhau. Vi mc nc trc l H
tl
= 101m H
gim ti Cng Sn l 2,6m; Vi H
tl
= 102 H
gim ti Cng Sn l 2,49m; Vi H
tl
= 103 H
gim ti Cng Sn l 2,18m
S lng cng trnh xy dng kh nhiu
(329 cng trnh) nhng cng trnh nh li chim
phn ln, trong c 55% cng trnh khai thc
bng lu lng c bn. Vi vng Ty Nguyn
ni chung v vng thng trung lu sng Ba
chim ti 2/3 din tch ton lu vc ni ring
c 6 thng ma kh v lng ma trong 6 thng
ny ch chim 10% tng lng ma m khai
thc phn ln l p dng l cha hp l. Vng
thng Ayun v thng ng Cam hin nay c
nhiu cng trnh khai thc ti l p dng s
dng ngun nc c bn ti vi mc bo
m cp nc di 70%.
Cc cng trnh xy dng khu vc
thng trung lu cn thiu lao ng khai thc.
Vng ti Ayun h, p Ayun thng, p
kx R vng thng ng Cam, khu ti
p Eatrol cng thiu ngun lao ng trm
trng. Cng trnh xy dng xong m cha c
rung m rng din tch ti. Nhn chung
nhng ni cng trnh xy dng c ng bo dn
tc thiu s th hiu qu m mang xy dng
ng rung, pht trin din tch ti cn hn
ch. Ngoi ra s phi hp gia cc ngnh thiu
cht ch cng vi cng tc nh canh, nh c
kinh t mi thiu ng b dn n mt s cng
trnh thu li trn lu vc sng Ba km pht
huy hiu qu. Mt s khu ti cha hnh thnh
ng rung cng l mt trong nhng nguyn
nhn lm cho cng trnh thu li cha pht huy
tt hiu qu.
Trong cng tc thit k khng ch trng
cng tc kho st cc ti liu c bn nht l khu
ti nn mt s cng trnh khi xy dng din
tch khu ti thng thp so vi thit k. u
t dn tri nhiu dn n mt s cng trnh
thiu vt t ngun vn nn thi cng ko di,
phn nhiu ch c u t phn u mi n
phn knh mng v cng trnh trn knh, vn
b ct xn nn phn no hn ch vic pht
huy sm hiu qu cng trnh. Cng tc qun l
khai thc, cng trnh phn cp cho x qun l
nhng cc cn b qun l cha am hiu v
nghip v v thiu tinh thn trch nhim. Cc
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471 466

tn ti nu trn cn sm c khc phc, c
nh vy mi pht huy ht nng lc ti cng
trnh thu li gp phn tng v tng nng sut
cy trng to nhiu sn phm hng ho gp
phn tng thu nhp lm giu cho ngi dn
trong lu vc sng Ba.
m bo cht lng nc, mi trng
vng h lu, trong tng lai khi tc th
ho, cng nghip ho ngy cng tng nhanh,
trnh tnh trng vo ma kh dng chy cn
kit dn n xm nhp mn, nhim ngun
nc do cc cht thi t cc khu dn c, cng
nghip, bi lp ca sng. Trong tnh ton nhu
cu nc n 2010, c xt n lng nc tr
li dng chy t nhin trong cc thng ma kh
ti cc v tr An Kh, ca sng Ayun, ca sng
Hinh v h lu p ng Cam. Lng nc
ny c ly bng lng dng chy nh nht
ng vi tn sut 90% ti cc v tr tnh ton.
Hin nay t trng GDP cng nghip trong lu
vc cn nh b (16%), cha hnh thnh cc khu
cng nghip tp trung, thiu c s h tng cng
nghip hin i. Cc ngnh cng nghip ch
yu l ch bin nng lm sn, cng nghip vt
liu xy dng. Yu cu nc cho cng nghip
c ly bng 15% lng nc sinh hot.
Lu vc sng Ba c 2/3 din tch t ai
nm vng thng v trung lu, dc sng
sui ln, c kh nhiu gnh thc vi chnh
lch t vi chc n vi trm mt rt thun li
cho vic xy dng cc cng trnh thu in va,
nh v ln. Ngun ti nguyn nc phong ph
cng vi yu t a hnh thun li cho vic b
tr xy dng cc cng trnh thu in. Cc kt
qu nghin cu gn y nht cho thy lu vc
sng Ba c th xy dng c 67 cng trnh
thu in va, nh v ln vi tng cng sut
lp my khong 854MW, in lng trung bnh
hng nm khong 3,9 t KWh.
Yu t quan trng nht lm gim i s
cn kit ca sng sui l qu trnh khai thc
ngun ti nguyn nc phc v nhu cu pht
trin kinh t x hi trong vng. Qua tnh ton
cn bng nc cho thy lng nc thiu tp
trung vo thi k ma kh, trong khi lng
nc tha vo ma l l kh ln. chng cn
kit cho dng chy sng sui trong lu vc, cn
u t xy dng nhiu cng trnh thu li, trong
cn c bit ch trng 4 cng trnh ln trn
dng chnh v dng nhnh ln l: H Thu in
An Kh-Kan Nk, h thu in KRng HNng,
h thu in sng Hinh, h thu in sng Ba
h.
2.2. nh gi mc tiu ca cc h cha sng
Ba
Trn lu vc sng Ba c rt nhiu h cha,
i su phn tch tt c cc h cha trn tht l
kh khn, do ta ch c th i phn tch mt
s h cha ln: sng Ba h, An Khe Kanak,
Ayun h, sng Hinh. Krng Hnng
2.2.1. nh gi mc tiu ca h cha sng
Ba h
H sng Ba H l mt h cha pht in
ln nht trn sng Ba [3]. y l mt h cha
li dng tng hp phc v cc mc tiu pht
in, ti, phng l v cp nc sinh hot. Nh
my thu in (NMT) sng Ba h c xy
dng trn a bn hai huyn sng Hinh v Sn
Ho tnh Ph Yn.
NMT sng Ba H l mt cng trnh li
dng tng hp. Mc tiu ca NMT ny gm:
- Mc tiu pht in: m bo mt cng
sut lp my l 220MW cng sut m bo vi
Q90% l 33,3MW v in nng bnh qun
nhiu nm E
0
= 825kwh.
- Mc tiu ti: NMT sng Ba h nm
thng lu p dng thu li ng Cam. Vi
dung tch ton b l 349,7 10
6
m
3
kh ln nn c
th tng cng lng nc ti cho p ng
Cam trong ma kit vi din tch ti m bo
l 19800ha.
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471 467

- Mc tiu phng l: NMT sng Ba h c
vai tr quan trng phng l cho h du, c bit
vng th x Tuy Ho. Tuy vy h cha sng Ba
h l loi cng trnh cp V v tng dung tch
349,710
6
m
3
l tng i nh so vi tng lng
l. V d l nm 1981 c W = 2,77 t m
3
v l
1993 c W = 2,6 t m
3
. Do tc dng phng
l ca n khng nhiu, ch yu l chng l
u ma v cui ma. Mc tiu chng l y
c thc hin vn l gii php sng chung v
thch nghi vi l. Khi NMT sng Ba h kt
hp vi 4 NMT khc th cng c tc dng h
thp mc nc h du.
- Mc tiu cp nc sinh hot: Mc tiu ny
c xem nh v ti cc vng cn cp nc nh
th x Tuy Ho c ngun nc ngm rt tt.
Hai mc tiu ph hp nht ca NMT ny l
pht in v ti v y c ngun thu nng
di do m bo pht mt cng sut lp my
N
LM
= 220 MW v E
0
= 825 10
6
kwh. ng thi
c iu kin a hnh l thung lng rng c th
xy h cha ln vi tng dung tch 349,710
6
m
3
.
ng thi y c sn cng trnh thu li
p ng Cam nn NMT sng Ba H, ch cn
iu tit b sung dng chy cho p ng Cam
l c th m bo ti ch ng cho 19800 ha
bng ti t chy.
2.2.2. nh gi mc tiu ca NMT An
Khe - Kanak
NMT An Kh - Kanak nm thng lu
sng Ba [4] ti a phn ca cc huyn Kbang,
An Kh thuc tnh Gia Lai v huyn Ty Sn
ca tnh Bnh nh. y l mt cng trnh lin
hp gm 2 cm cng trnh An Kh v Kanak.
Cng trnh NMT An Kh - Kanak l mt cng
trnh li dng tng hp. Mc tiu ca cm cng
trnh ny bao gm:
- Mc tiu pht in: m bo pht mt
cng sut lp my tng cng l 173 MW v
in nng bnh qun nhiu nm l
699,810
6
kwh.
- Mc tiu ti: NMT ny c 2 mc tiu
ti: ti ti ch cho vng An Kh v chuyn
nc ti cho vng nam Sng Cn thuc tnh
Bnh nh. Hai din tch l 4703ha An Kh
v 14200 ha la hai v lu sng Kn. Lng
nc chuyn qua sng Cn l Qp=90%
=11,3m3/s v Qp=75% =14,2m3/s. V ti ti
ch, dn sinh cng nghip cho th x An Kh
cn lng nc 4410
6
m
3
.
- Mc tiu cp nc cho cng nghip, sinh
hot: Nc ca NMT An Kh - Kanak phc
v pht trin cy cng nghip c ph, cao su
ca tnh Gia Lai v cp nc cho sinh hot.
- Mc tiu chng l: NMT An Kh -
Kanak c 2 phng n phng l: phng n 1:
An Kh v sng Hinh; phng n 2: An Kh
vi 4 NMT khc, phng n 2 ny c tc
dng h thp mc nc lu lng h lu sng
Ba nh trnh by trn.
NMT An Kh - Kanak l mt cng trnh
c cc mc tiu s dng tng hp v thng
ngun sng c lng ma kh ln t 1768 -
1821mm/nm, c a hnh thun li xy h
cha trn 2 thung lng ln vi tng dung tch l
329,610
6
m
3
. V thng ngun sng Ba c
ngun thu nng di do c th m bo cng
sut lp my l 173MW v E
0
= 699,810
6
kwh.
ng thi thng ngun sng Ba ti An Kh -
Kanak c ngun nc ln, u nc cao c th
m bo ti t chy v chuyn nc qua pha
ng Trng Sn, b sung nc cho sng Kn
tng kh nng ti cho tnh Bnh nh sau
khi pht in. y l mt phng n ti u
trong khai thc ti nguyn nc.
Ring mt mnh NMT An Kh - Kanak
khng c tc dng chng l nhiu cho h du m
n ch c chng l bo v an ton cho cng
trnh. Khi nh my ny kt hp vi NMT
khc th c kh nng chng l cho h du. y
c hai phng n phng l cho h du l:
Phng n 1: An Kh - Kanak v sng Hinh;
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471 468

phng n 2 gm 5 h cha phi hp vn hnh.
Theo cc kt qu tnh ton t [1,4], khi 5 h
phi hp th c th ct l sm tng ng vi
tn sut 1%, 5% v 10% gim t 1037m
3
/s
xung 355,6m
3
/s ti Cng Sn i vi l c tn
sut 1%; gim t 2642m
3
/s xung 823m
3
/s ng
vi l 5%; gim t 2203m
3
/s xung 663m
3
/s
ng vi tn sut l 10%. Mc gim nc l
ti Cng Sn cn ph thuc vo mc nc
trc l ti NMT sng Ba h. Vi cc mc
nc trc l ti h cha sng Ba h l 101m,
102m, 103m, 104m, 105m th mc nc h lu
sng Ba ti cc a im Cng Sn, Ho Bnh
Ty, Ho nh ng, Ho Thng, Ho An, Ph
Lm s b h xung. i vi trn l chnh v
mt mnh NMT An Kh - Kanak c tc dng
khng ng k v tng lng l dy rt ln.
2.2.3. nh gi mc tiu ca MNT Ayun
h
NMT Ayun h nm thng ngun sng
Ba [5, 6] thuc a phn ca huyn MangYang,
aka, Ch S, tnh Gia Lai. NMT Ayun h
khng phi l mt cng trnh li dng tng hp.
Tuy vy da vo hot ng thc t ca cng
trnh khi a vo hot ng t nm 2000 cho
thy y vn l mt cng trnh li dng tng
hp phc v pht in, ti, phng chng ng.
Trn tuyn cng trnh NMT Ayun h c hai
i din ca hai cng ty in lc min Trung v
cng ty thu nng tnh Gia Lai.
- V mc tiu pht in: NMT Ayun h c
cng sut khng ln vi N
Lm
=3,0 MW v E
0
=
2410
6
kwh. NMT ny c hai t my cng sut
1 t my l 1,5 MW. Ngun in ca NMT
ny ho vo mng li in a phng v
quc gia, y l mt NMT loi nh nn
NMT ny pht in khng phi l mc tiu
chnh.
- V mc tiu ti cp nc: NMT Ayun
h vi tng dung tch h kh ln 253 10m
3
nn
mc tiu ti v cp nc ca cng trnh l
mc tiu chnh. Cng trnh ny m bo ti
cho ton b vng ti Ayunpa vi din tch
ti l 38475ha thuc. Qua kho st thc a
thng 5/2009 cho thy y l mt cng trnh
ti t chy ht sc thun li. Vng ti
Ayunpa hon ton ti ch ng. Ngoi din
tch ti theo quy hoch l 38473ha cn tng
din tch ti ca cng trnh ln 42000 ha theo
yu cu ca tnh Gia Lai: y l vng cy cng
nghip, c ph, cao su v cnh ng la nc
nn rt cn nc ti ca h Ayun h. Cng
trnh cn cp nc cho ton b th trn Ayunpa.
- V cc mc tiu khc: V mc tiu tiu
chng ng ngp lt: Trc nm 2000 vng ny
l vng trng, hng nm t thng 9 n thng
11 thng xuyn b ngp. Nhng sau nm 2000
khi NMT Ayunha i vo hot ng th ton
b vng ny khng ngp na.
- V nui trng thu sn: Hin nay trong
vng c mt din tch mt h kh ln. ng vi
mc nc dng bnh thng 204m to ra
mt mt h nhn to 37km
2
c th tn dng
nui trng thu sn. Hin nay c mt cng ty
Ayunpa nui c trn h. Cc loi c c th l
c m, tri, chp v hng nm cho sn lng
hng trm tn cung cp cho th x Plycu tnh
Gia Lai.
NMT Ayun h c mc tiu li dng tng
hp, ch yu l ti v pht in. Ngoi ra cn
c cc mc tiu khc l tiu ng, nui trng
thu sn v ci to mi trng.
V mc tiu ci to mi trng khng c
cp trong quy hoch nhng vi cnh quan
mt nc 37km
2
lm cho vi kh hu bin i
v c tc dng kch thch du lch pht trin.
Hin nay c cng ty pht trin du lch sinh
thi ca h Ayunha.
2.2.4. nh gi mc tiu ca NMT Sng Hinh
NMT sng Hinh nm trn mt nhnh sng
pha hu ngn sng Hinh [7] thuc a phn
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471 469

huyn Sng Hinh tnh Ph Yn. y l mt
vng c lng ma ln nht trn sng Ba vi
lng ma bnh qun nhiu nm l 2570,0mm
- V mc tiu pht in: y l NMT loi
va vi N
LM
= 31,5 MW v E
0
= 403,6.10
6
kwh.
in nng ca NMT ny ho vo mng
in quc gia v tnh Ph Yn. Qun l ngun
in ny do Tng cng ty in lc Vit Nam v
Cng ty in lc min Trung.
- V mc tiu ti: NMT sng Hinh m
bo ti cho 10464 ha din tch ca huyn Sng
Hinh. Hin nay cng trnh i vo hot ng
v phc v ti cho din tch trn.
- V mc tiu phng chng l: Cng nh
cc NMT trn, NMT sng Hinh mt mnh
tc dng ct l rt t. N thc s hiu qu khi
phi hp vi NMT sng Ba h v cc NMT
khc.
- V cc mc tiu khc: Mc tiu khc nh
mi trng thu sn, bo v mi trng khng
c nhc ti trong d n NMT sng Hinh.
2.2.5. nh gi mc tiu ca NMT Krng
Hnng
NMT Krng Hnng nm trn nhnh sng
Eakrng Hnng [2] thuc a phn huyn sng
Hinh (Ph Yn) v cc huyn Eaka, Mrc
(c Lc). V tr tuyn p cch th t n Cng
Sn (Ph Yn) khong 30km v pha Ty-Ty
nam. H ang c xy dng vi dung tch
ton b l W=356,6.10
6
m
3
v dung tch hiu
dng l W=242,9.10
6
m
3
. y cng l mt vng
ma ln v thng c l ln.
-V mc tiu pht in: y l mc tiu
chnh, vi N
LM
=66MW v in nng hng nm
l 264,6. 10
6
kwh.
-V mc tiu ti. Chu trch nhim cp
nc ti cho 12.000ha ca cc huyn trn
thuc 2 tnh Ph Yn v c Lc.
-V ct l. Cng nh cc h thu in khc
trn sng Ba, nhim v ct l khng phi l
chnh, n ch pht huy tc dng khi phi hp
vi cc h cha khc theo phng n 2 (PA2)
vi mc nc trc l xung thp hn mc
nc dng bnh thng 5m, tc l cao trnh
260m.. H ang xy dng v cha c quy trnh
iu hnh.
Cc mc tiu khc khng c cp.
2.3. nh gi mc tiu ca ton b h thng
NMT trn sng Ba
Trong quy hoch thu li sng Ba [1]
a ra mc tiu ca ton b h thng gm mc
tiu pht trin kinh t x hi v mc tiu pht
trin ti nguyn nc. Chin lc s dng v
bo v ngun nc n nm 2020 nhm p
ng yu cu cp nc cho cc ngnh kinh t x
hi nh sn xut nng nghip, dn sinh, cng
nghip, th, nui trng thu sn, pht trin
thu in, ng thi phng chng cn kit, xi
l, hn ch thin tai ng l, bo v mi trng..
Qua phn tch tnh ton tnh hnh l lt
vng h lu sng Ba c th ni l y kh
trm trng. Kt qu tnh ton thy lc s b [1]
cho thy:
Khi h cha Sng Ba h i vo hot ng
cng vi 2 h cha hin ti Sng Hinh v Ayun
h s c tc dng ct gim l ng k cho h
du. H cha Sng Ba h c th ct c khong
30% dung tch l chnh v tn sut 10% n h
nu mc nc trc l ca h thp hn mc
nc dng bnh thng 4m. Tuy nhin trong
trng hp ny nu sau l h khng tch c
y h th tn tht in nng s rt ln. Hn
na, trong trng hp ny din tch h du b
ngp vn rt ln khong 16000 ha, ch gim
khong vi trm ha so vi trng hp hin
trng ch c h Sng Hinh v Ayun h. Nu c
thm cc h Krng Nng v Ka Nak, mc nc
l chnh v trong tt c cc trng hp tnh ton
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471 470

tng ng vi tn sut 1%, 5% v 10% u ln
hn bo ng I. Qua cc kt qu tnh ton cho
thy rng cc h cha thng ngun khng th
chng trit l chnh v cho h du m ch c
th lm gim mc nc l m thi, nhng cng
khng th gim mc nc xung di mc bo
ng I, cn din tch ngp lt cng nh mc
ngp vn rt ln. Do iu kin a hnh trc
mt cha th xy dng h thng phng
chng l nn vic chuyn i ma v trnh
l chnh v l vic lm cn thit gim nh
tn tht ngp lt cho h lu sng Ba
i vi l sm, trong trng hp c thm
h Sng Ba h so vi hin trng th tc dng
gim l cho h du rt tt. Ch cn mc nc
trc l h Sng Ba h bng vi mc nc
dng bnh thng l c th gim mc nc
l ti Cng Sn v Ph Lm xung di bo
ng I trong cc trng hp tn sut l >5%.
Vi tn sut l 1%, gim mc nc l ti
Cng Sn xung di bo ng I cn mc
nc trc l h Sng Ba h mc thp hn
102m. Khi c thm h Krng Nng v Ka Nak,
mc nc ti Ph Lm trong tt c cc trng
hp tnh ton u thp hn bo ng I t (1,2-
1,4)m. Cn mc nc ti Cng Sn ch ln hn
bo ng I trong trng hp khi c l 1% v
m mc nc trc l h Sng Ba h bng vi
mc nc dng bnh thng.
Cc mc tiu ca h thng thu in trn
sng Ba cp mt cch y trong hai
vn c bn ca pht trin kinh t x hi v
pht trin ti nguyn nc trn lu vc. Tuy
nhin do cc h cha thuc quyn qun l ca
cc n v rt khc nhau, khng c mi lin h
cht ch vi nhau nn cc mc tiu cng rt
khc nhau. Mi h cha c mt mc tiu ring
thng l khng ng b, c khi mu thun
nhau. Trn lu vc cng khng c Ban Qun l
chung nn khng c s ch huy thng nht. Do
d hiu qu ca cc h cha b hn ch, vn
ngp lt v cn kit nc ti h lu khng c
gii quyt tho ng. Thc t iu hnh v hin
trng ngp lt trong trn l u thng 11/2009
do nh hng cn bo s 11 (Mirinae) m d
lun rt quan tm ni ln iu .
Ngoi ra cc h cha nh khc cng gp
phn nh hng n tnh hnh kinh tx hi
trn lu vc v cn c xem xt.
3. Kt lun
S h cha trn sng Ba c xy dng
ngy cng nhiu, trong c nhng h cha
ln. Tuy nhin v nhng mc tiu ring v thiu
s ch huy thng nht nn hiu qu ca h
thng h cha ny i vi kinh tx hi trn
lu vc cn hn ch. Vi quy m hin ti kh
nng ct l ca cc h cha thy in sng Ba
rt hn ch. Mun nng cao hiu qu ct l
cng nh cp nc bo m nhu cu cn phi
iu hnh hp l, kt hp vi d bo kh tng
thy vn chnh xc kp thi. V vy cn thit
phi c mt quy trnh v cng ngh iu hnh
lin h cha v mt Ban qun l chung [8,9],
tng t nh ca h thng h cha trn lu vc
sng Hng [8], phi hp cc mc tiu, v
nu cn c th iu chnh cc mc tiu, nhm
t hiu qu cao nht m bo ngn l, chm l,
an ton vn hnh h cha v s dng hp l ti
nguyn nc v ma kit lu vc sng Ba.
Bi bo ny c thc hin vi s h tr
ca ti KC.08.30/06-10.
Ti liu tham kho
[1] Vin Quy hoch thu li, Quy hoch tng hp
lu vc sng Ba, H Ni, 2005.
[2] PECC1, Quy hoch bc thang thu in sng
Ba, H Ni, 2002
[3] PECC1, Thit k k thut thu in sng Ba h,
H Ni, 2005.
N.H.Khi,N.V.Tun/TpchKhoahcHQGHN,KhoahcTNhinvCngngh25,S3S(2009)461471

471
[4] PECC1, Thit k k thut thu in AnKh-
Kanak, H Ni, 2004.
[5] PECC1, Thit k k thut thu li Ayun h, H
Ni, 1989.
[6] PECC1, Thit k k thut thu in Ayun h, H
Ni, 1998.
[7] PECC1, Thit k k thut thu in sng Hinh,
H Ni, 1992.
[8] Nguyn Tun Anh, Xy dng quy trnh vn hnh
lin h cha trn sng v sng L m bo
an ton chng l ng bng Bc B v an ton
cng trnh khi c cc h Thc B, Ho Bnh,
Tuyn Quang, Bo co tng hp, H Ni, 2007.
[9] S.K.Jain, V.P.Singh, Water Resources system
planning and management, Elsevier, 2003.

Evaluating role and objective of reservoirs in Ba river basin
Nguyen Huu Khai, Nguyen Van Tuan
Faculty of Hydro-Meteorology & Oceanography, College of Science, VNU
334 Nguyen Trai, Hanoi, Vietnam

This paper present role assessment of reservoirs in Ba river basin for flood prevention, enegy
generation, water supply serving social- economic development, conservating environment in
cachment and water diversion to other cachments. Analysing and assessing current objective of each
reservoir and conjunctive reservoirs system, correspondence in their operation for general purposes.
On this base, puting forward needfull changes of objective and operation of all system to flood
prevention, flood retarding, safety for reservoir operation and to use sensibly water resources in lowest
season on Ba basin, satisfying hamonous benefis and having most effictive.